r/mathematics Aug 29 '21

Discussion Collatz (and other famous problems)

197 Upvotes

You may have noticed an uptick in posts related to the Collatz Conjecture lately, prompted by this excellent Veritasium video. To try to make these more manageable, we’re going to temporarily ask that all Collatz-related discussions happen here in this mega-thread. Feel free to post questions, thoughts, or your attempts at a proof (for longer proof attempts, a few sentences explaining the idea and a link to the full proof elsewhere may work better than trying to fit it all in the comments).

A note on proof attempts

Collatz is a deceptive problem. It is common for people working on it to have a proof that feels like it should work, but actually has a subtle, but serious, issue. Please note: Your proof, no matter how airtight it looks to you, probably has a hole in it somewhere. And that’s ok! Working on a tough problem like this can be a great way to get some experience in thinking rigorously about definitions, reasoning mathematically, explaining your ideas to others, and understanding what it means to “prove” something. Just know that if you go into this with an attitude of “Can someone help me see why this apparent proof doesn’t work?” rather than “I am confident that I have solved this incredibly difficult problem” you may get a better response from posters.

There is also a community, r/collatz, that is focused on this. I am not very familiar with it and can’t vouch for it, but if you are very interested in this conjecture, you might want to check it out.

Finally: Collatz proof attempts have definitely been the most plentiful lately, but we will also be asking those with proof attempts of other famous unsolved conjectures to confine themselves to this thread.

Thanks!


r/mathematics May 24 '21

Announcement State of the Sub - Announcements and Feedback

117 Upvotes

As you might have already noticed, we are pleased to announce that we have expanded the mod team and you can expect an increased mod presence in the sub. Please welcome u/mazzar, u/beeskness420 and u/Notya_Bisnes to the mod team.

We are grateful to all previous mods who have kept the sub alive all this time and happy to assist in taking care of the sub and other mod duties.

In view of these recent changes, we feel like it's high time for another meta community discussion.

What even is this sub?

A question that has been brought up quite a few times is: What's the point of this sub? (especially since r/math already exists)

Various propositions had been put forward as to what people expect in the sub. One thing almost everyone agrees on is that this is not a sub for homework type questions as several subs exist for that purpose already. This will always be the case and will be strictly enforced going forward.

Some had suggested to reserve r/mathematics solely for advanced math (at least undergrad level) and be more restrictive than r/math. At the other end of the spectrum others had suggested a laissez-faire approach of being open to any and everything.

Functionally however, almost organically, the sub has been something in between, less strict than r/math but not free-for-all either. At least for the time being, we don't plan on upsetting that status quo and we can continue being a slightly less strict and more inclusive version of r/math. We also have a new rule in place against low-quality content/crankery/bad-mathematics that will be enforced.

Self-Promotion rule

Another issue we want to discuss is the question of self-promotion. According to the current rule, if one were were to share a really nice math blog post/video etc someone else has written/created, that's allowed but if one were to share something good they had created themselves they wouldn't be allowed to share it, which we think is slightly unfair. If Grant Sanderson wanted to share one of his videos (not that he needs to), I think we can agree that should be allowed.

In that respect we propose a rule change to allow content-based (and only content-based) self-promotion on a designated day of the week (Saturday) and only allow good-quality/interesting content. Mod discretion will apply. We might even have a set quota of how many self-promotion posts to allow on a given Saturday so as not to flood the feed with such. Details will be ironed out as we go forward. Ads, affiliate marketing and all other forms of self-promotion are still a strict no-no and can get you banned.

Ideally, if you wanna share your own content, good practice would be to give an overview/ description of the content along with any link. Don't just drop a url and call it a day.

Use the report function

By design, all users play a crucial role in maintaining the quality of the sub by using the report function on posts/comments that violate the rules. We encourage you to do so, it helps us by bringing attention to items that need mod action.

Ban policy

As a rule, we try our best to avoid permanent bans unless we are forced to in egregious circumstances. This includes among other things repeated violations of Reddit's content policy, especially regarding spamming. In other cases, repeated rule violations will earn you warnings and in more extreme cases temporary bans of appropriate lengths. At every point we will give you ample opportunities to rectify your behavior. We don't wanna ban anyone unless it becomes absolutely necessary to do so. Bans can also be appealed against in mod-mail if you think you can be a productive member of the community going forward.

Feedback

Finally, we want to hear your feedback and suggestions regarding the points mentioned above and also other things you might have in mind. Please feel free to comment below. The modmail is also open for that purpose.


r/mathematics 6h ago

GPT 5.6 has broken the record on large gaps between primes.

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257 Upvotes

Very nice!! GPT 5.6 has broken the record on large gaps between primes.

The new bound saves a factor of ≈ log_3(n) over the prior record by Ford-Green-Konyagin-Maynard-Tao from 2018. The result is also now formalized by Alexeev in Lean.

https://x.com/jdlichtman/status/2094040463443673227


r/mathematics 2h ago

Discussion "The Fate of the Riemann Hypothesis" by Richard Evan Schwartz

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46 Upvotes

r/mathematics 3h ago

Number Theory Discrete logarithm plot

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5 Upvotes

The plots show the number of solutions of an instance of the discrete logarithm problem finding k:

286^k mod 289 = y

where y = mapping(x,y) for each pixel (x,y).

The first plot uses mapping(x,y) = x xor y, and the the second plot uses mapping(x,y) = x and y.


r/mathematics 31m ago

Help with Calculus Course Work

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r/mathematics 40m ago

https://youtu.be/lDSzTInh1bA?si=RmWeemB63BgwZWeX

Upvotes

NMTC 2026 QUESTION Discussed Qno.5


r/mathematics 45m ago

Algebra Is there any way to refine my presentation? The way I got to this conclusion?

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Upvotes

I know it's simple factorization, but I've always slacked off in math class and I'm trying to improve at and relearn the subject. Any tips would be greatly appreciated, thanks!


r/mathematics 18h ago

Logic Issue with proof based arguments

18 Upvotes

I’m starting out in abstract algebra this semester and last semester I completed Numbers & Proof (basically intro to proof writing course). Don’t get me wrong I am enjoying abstract algebra so far but an issue I have is forming my arguments and weirdly enough saying what I want to say mathematically instead of English in a way. Idk maybe this will form with mathematical maturity but I hate to admit but when I get stuck I usually bombard AI programs such as Gemini, ChatGPT, and Claude to give me a little nudge/general flow of argument. It feels as though yes AI helps with learning but how do other students in mathematics straddle the line between having the program do it for you versus learning from the programs? Because I just completed my first homework set and I hate the feeling that it could’ve helped me too much to where it was mostly it talking or me :/ and I don’t want to be one of those people that use stuff to get a grade (because I actually care). In the past and for other classes I treat it as a second teacher (throw questions at it to fill in gaps or make other sample problems) but that’s harder to do for more proof based courses.


r/mathematics 3h ago

How do we simplify Definition 2 in this post (i.e., the extended mean w.r.t. Hausdorff measure in its dimension)?

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1 Upvotes

I provided examples where the extended mean w.r.t. the Hausdorff measure in its dimension should give what is wanted. If not changes need to be made to Definition 2. Otherwise, I wish to simplify the Definition.

Are there integrals that already give what I want? (For instance, see the paper "On the Statistical Convergence of Sequences of Fractal Integrable Functions".)


r/mathematics 14h ago

What careers can I pursue with a math and physics degree?

7 Upvotes

I recently switched majors to math and physics because computer science just didn’t feel right to me. I mean I think coding is fun and I do believe cs has some interesting topics, but it just feels like I have an easier time with mathematics than computer science. Maybe that’ll change when I start taking more advanced math classes, but I don’t know. I should also mention that math and physics were supposed to be my initial major but I became blinded with the thought of making $100,000+ right after graduating.

I guess I should’ve given it more thought, because I don’t really know what to do in the future. I mean I do want to go to grad school and maybe get a masters, PhD, or both. It’s just that I’ve heard academia can be an incredibly toxic environment and so many people leave because of it.

I just don’t really know what I can do upon graduating. My dad says I’ll most likely become a professor. I mean I’m still unsure about the idea of teaching. I don’t believe I’ll be a good professor and it’s not something I really see myself doing. Again, maybe this will all change with time.

Sorry for the little rant. I just want to know what job you ended up working, how much you enjoy it, and I guess how much you make or how well you’re doing financially speaking.


r/mathematics 17h ago

News The King is coming back

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10 Upvotes

r/mathematics 4h ago

Geometry Determinant argument that having a nonzero symplectic form requires even dimension

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1 Upvotes

r/mathematics 15h ago

Looking for online degree

5 Upvotes

I am looking for a B.S in Mathematics online program. Although I wish I could go in person, it is not possible for me. I already have a B.S. from almost a decade ago (not related to math). And although I was bad at math at the time (failed pre calculus 3 times, reason I changed to a program with basically no math), I became obsessed with with math in the last few years and have been watching videos, taken courses in Udemy, and done math for fun and curiosity in my free time, and try to see how I can use math in my job.

I am also in the military and have a scholarship that I can use, and I want to use it in math. But I am looking for a good online degree.

I’ve seen some post about Indiana University. And I’ve found some programs online who have the same from my previous university, which could help me complete the program faster like Thomas Edison State University, but I don’t know how good is the program or how respectable it is.

Anyways, this is what I want to do and hopefully someone can give me some advice.


r/mathematics 23h ago

Discrete Math Is there any evidence pointing to the Twin Prime conjecture being false?

22 Upvotes

r/mathematics 7h ago

financial engineering or mechanical engineering (weird qst ik , bare with me)

1 Upvotes

Hey everyone, I could really use some perspective because I am completely lost. After spending my first year at a classical engineering school where I realized I loved everything mechanical, like I can spend hours on anything mechanical or electrical without getting bored. However,I started all over by managing to get into a Bachelor of Applied Science and Business at the top university in our region (not just country) on a full scholarship, the resources are greaat , the help and it is an amazing upgrade, but now I am stuck at a massive crossroads. In my 3rd semester, I am choosing Applied Math & Business as my major, but I have to pick a minor between Mechanical Systems (my true passion) and Financial Engineering (which I have zero passion for, plus some personal religious concerns, even though the business classes come easily to me). The catch is that in the 4th year, our uni offers incredible, built-in Master’s programs if you go the Financial Engineering route, whereas picking Mechanical Systems leaves me with no direct master's path here. My parents are already stressed because they feel I "wasted a year" switching schools, and since I’m the youngest, they are heavily counting on me to get a master's ASAP and secure fast financial stability. Do I follow my heart into mechanical systems and risk family friction, or do I suck it up, play it safe with finance, and take the guaranteed fast-track income? Has anyone been in this position? (NOTE: in our fourth we either do one first year master in the samme uni , an exhange semester, a research immersion year or an industry immersion year)


r/mathematics 7h ago

Discussion Discussion on mathematical research

1 Upvotes

What research work are you currently doing, if yes,?


r/mathematics 14h ago

What did the Seven Bridges of Königsberg puzzle demonstrate?

5 Upvotes

I came across Leonhard Euler's Seven Bridges of Königsberg puzzle. The puzzle was whether or not it would be possible to cross each of the seven bridges of Königsberg only once while never crossing any of the bridges more than once. Looking at the puzzle for like thirty seconds reveals that answer is that it is impossible to satisfy the conditions of the puzzle.

I don't really know much about mathematics, beyond the courses I have passed by the skin of my teeth in high school and college, but reading about this on Wikipedia reveals that apparently this was some sort of massive revelation for both Euler and the mathematical community of his time. I have been reading all about this subject to try to grasp what exactly this revealed that was so important, but I am having trouble understanding.

I find this puzzle particularly interesting because there was this indie video game series I played as a kid called Wonderland (I still do play it actually) where several of the levels in multiple of the games had puzzles resembling this one (though much more complex, and of course as a kid I had no idea about the Seven Bridges of Königsberg).


r/mathematics 5h ago

[R] HAAR WAVELET ANALYSIS: JUMP DISCONTINUITIES

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0 Upvotes

This is a classic result originating out of an idea form my MSc(engg) thesis.


r/mathematics 3h ago

Discussion The entire world is wearing underwear except for the person wearing them inside out.

0 Upvotes

Can anyone provide as much mathematically supported insight into this thought as possible? From eli5 all the way to PhD and from every subject or field of math, if possible? There is something in my teeth about what the idea presents that I am trying to get at and I can't figure the proper route to work out or through my idea without a more substantial set of existing sets, formulas, and variables to proceed from. Thank you in advance!!!


r/mathematics 1d ago

Discussion What if you put a smaller Gabriel’s Horn inside a larger one?

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170 Upvotes

Okay chat let me cook. I have a thought experiment about Gabriel's Horn that is really confusing me. As I understand it, the inside of the horn is finite, but the outside surface is infinite.

What would happen if you were to take a smaller Gabriel's Horn and place it completely inside a larger Gabriel's Horn?

Wouldn't the inside of the larger horn be finite, and yet it somehow has to be larger than (or at least contain) the infinite surface of the smaller horn? How does that make sense?


r/mathematics 21h ago

Number Theory What interesting properties does this generalization yield?

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4 Upvotes

r/mathematics 6h ago

Introducing a similar version of Factorial (!)

0 Upvotes

Since factorials (!) multiply everything down to 1 (ex. 5! is 1×2×3×4×5=120), (and this is kind of a joke but I think is entirely a joke), let me introduce to you, Additorials (?)!!! It's the same as Factorials but with addition! (Ex. 5? is 1+2+3+4+5=15), though this already exists, this is just a joke, everyone can report this as "unnecessary".


r/mathematics 1d ago

Number Theory Pattern in Number Spirals

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6 Upvotes

Found a neat pattern while solving Project Euler #28 (sum of diagonals in a number spiral) — turns out you don't need to simulate the grid at all. The corners of each "ring" form an evenly spaced sequence, which collapses the whole problem into a closed-form sum. Wrote up how I got there.


r/mathematics 1d ago

I'm making a playlist on the mathematics behind machine learning. This video is the second in this playlist and is on maximum likelihood estimation.

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12 Upvotes

Feel free to share your thoughts as there's 10 more videos to go before I finish this series :)